Find the value of the smallest natural number X if X^381 is divisible by 11.

If b is the mean proportion between 2 and 8, then which of the following can be a value of b?

The system of equations 2x + ky = 11 and 5x + 7y = 5 has no solution if the value of k is:

Choose the word that means 'that which cannot be done without'.

Look carefully for the pattern, and then choose which pair of numbers comes next.

42, 40, 38, 35, 33, 31, 28

The slant height of a right circular cone is 10 m and its height is 8 m. Find the area of its curved surface.

 A and B invest in a business in the ratio 3 : 2. If 5% of the total profit goes to charity and A's share is Rs. 855, the total profit is : 

 The ratio between the perimeter and the breadth of a rectangle is 5 : 1. If the area of the rectangle is 216 sq. cm, what is the length of the rectangle? 

A grocer has sales of €6435, €6927, €6855, €7230, and €6562 for 5 consecutive months. How much sales must the grocer have in the sixth month to achieve an average monthly sales of €6500?

A, B, C rent a pasture. A puts 10 oxen for 7 months, B puts 12 oxen for 5 months and C puts 15 oxen for 3 months for grazing. If the rent of the pasture is Rs. 175, how much must C pay as his share of the rent?